Snowshoe with Sole Comprising Crampon Areas

ABSTRACT

A snowshoe with a base structure forming a flotation zone having a plurality of transverse tread elements ( 20 ) of substantially elongate shape. The tread elements ( 20 ) have front lateral walls ( 25 ) and rear lateral walls ( 26 ),In the front portion of the flotation zone, at least a portion of the tread elements ( 20 ) have a rear lateral wall ( 26 ) that is inclined toward the rear of the snowshoe; and in the rear portion of the flotation zone, at least a portion of the tread elements ( 20 ) have a front lateral wall ( 25 ) that is inclined toward the front of the snowshoe.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a snowshoe comprising a base structureforming a foot zone and a flotation zone. The flotation zone comprises alateral overhang on each side of the foot zone and is extended towardsthe rear of the foot zone to form a tail. The snowshoe exhibitsadvantageous properties of flexibility and ergonomics.

PRIOR ART

Snowshoes are items that have been known for many years. They wereinitially designed in order to allow individuals to travel over groundcovered with a large quantity of snow. They are also very widespread innorthern countries which are often affected by heavy snowfalls. However,these extreme conditions are becoming ever less representative of theactual conditions in which snowshoes are currently used. Specifically,nowadays, they are used primarily by hikers in a “sport and leisure”context. As those engaging in such practices are of widely varying skilllevel, from beginner to expert, the requirements for each of the levelsdiffer greatly. This lack of uniformity is forcing manufacturers toceaselessly develop new products in order to best meet the variousexpectations. There are therefore nowadays several ranges of products,each having their own specific advantages. However, manufacturers arestill looking for innovative solutions capable of providing greatercomfort and increasing dynamic performance.

In general, snowshoes are made up of a latticework, of a tip, of a rearportion and of a binding system. This basic configuration allows foreasy travel over snow because of the better flotation, preventing theuser from sinking into the snow.

The tip and tail are also designed to allow for easy walking, with arolling of the foot, making walking easier by making it more natural.However, this objective is generally not achieved because of thebulkiness of the snowshoes, their shape and surface area often makingthem rather unmanageable. Thus, in use, the snowshoe-wearer often findswalking strenuous because the walker has to lift up the front of thesnowshoe, draw the snowshoe forwards and then place it down flat,without being able to roll the foot in a natural and ergonomic way.These constraints mean that the vast majority of users quickly showsigns of fatigue and/or of discomfort even after a short expedition.

Many users use snowshoes only very occasionally, for example during astay at a winter resort. In such cases, the snowshoes are hired out fromspecialist stores. In order to conform to profitability requirements,the hirers often wish to keep the equipment for as long as possible anddemand that the manufacturers produce products that are highly robustand durable. In response to these requirements, the manufacturers offersnowshoes that have a rigid structure.

This aspect comes with several disadvantages. Firstly, the lack offlexibility makes the snowshoes somewhat unergonomic. A snowshoe with arigid structure does not conform to the shape of the boot or of thesurface on which it is placed. Secondly, the materials used are selectedwith the prime objective of meeting requirements of lightness of weight,durability and stiffness. These types of material generally offer poor,or else mediocre, traction performance. In order to mitigate the effectof these limitations, several products are fitted with metal insertsintended to increase grip on snow or on ice. This feature is practicalfor these types of ground, but users may have to walk on hard ground,for example when crossing a road, and in such instances the snowshoesare then not at all suitable.

Finally, in order to compensate for the stiffness of the snowshoe andmake walking easier, the snowshoes are either of twin-tip type, namelyhaving a turned up tip at the front of the foot and another at the rear,or have a very turned-up tip at the front combined with a substantiallyplanar rear portion. These characteristics allow the user to walk morenaturally than with snowshoes that are completely flat. However, thefront tips force the user to lift the foot relatively high, requiringextra effort for each step. Without this movement, which is not natural,the front tip may strike an obstacle and/or become snagged on the groundand cause a fall. Furthermore, because feet have a slight turnout, therear tips (tails) may interfere with one another when walking. If theyknock together, there is then a risk of a fall.

In another aspect, again with a view to improving user comfort whenwalking in snowshoes, snowshoe ergonomics have been improved alongvarious lines of development. One of these lines is concerned with thegrip of the snowshoes by using soles made of elastomer equipped withindentations and/or with studs.

For example, document WO9506502 describes a snowshoe formed of asemi-flexible deck comprising means of connection for connecting auser's boot to the deck. The deck is moulded in a semi-flexible plasticsmaterial which is able to flex with the boot, such as for example in athermoplastic polyurethane. The hardness of the deck is comprisedbetween 50 and 90 Shore D at around 18° C. This characteristic resultsin a snowshoe that is relatively flexible, but not flexible enough toachieve true comfort when rolling the foot. Furthermore, the undersideface of the deck is formed with indentations and/or projections toimprove the traction when using the snowshoes. The circular openingseach contain an oval recess, these being oriented according to theirlocation on the underside face. The semi-flexible plastics material andthe indentations do improve the level of grip of the snowshoes, althoughthere is still room for improvement.

Document FR2743501 describes a shoe for walking, particularly on snow,made up of a substantially planar deck equipped with means forreversibly securing the foot of the user to said deck, which is made ofcellular elastomer. This snowshoe is lightweight and stiff, but with acertain degree of elasticity, and with good grip. The underside facecomprises studs produced by moulding and distributed according to theload distribution in use. These features allow the user to have asnowshoe that is more comfortable than conventional snowshoes, and alsoto enjoy better grip because of the distribution of the studs. However,the grip provided by the elastomer studs and their distribution do notgive the snowshoe optimal purchase. In addition, the front part of thesnowshoe forces the user to raise the foot higher than usual, and thismay lead to premature fatigue.

The invention provides various technical means for remedying thesevarious drawbacks.

SUMMARY OF THE INVENTION

First of all, a first objective of the invention is to provide asnowshoe that is flexible and ergonomic and has good traction andbraking performance.

Another objective of the invention is to provide a snowshoe that hasgood flight ability and optimal purchase on all types of ground,particularly on a covering of snow that is more or less deep.

Yet another objective of the invention is to provide a snowshoe thedesign of which is simple and inexpensive.

Finally, another objective of the invention is to provide a snowshoethat makes walking easier and that has the necessary characteristics toallow the user to walk as naturally as possible.

In order to achieve this, the invention provides a snowshoe comprising abase structure forming a flotation zone, said snowshoe comprising acontact face and a securing face, said flotation zone comprising, on thecontact-face side:

-   -   (i) a plurality of tread elements made of elastomeric material        and arranged over all or part of the foot zone, said tread        elements being of substantially elongate shape, passing across        the flotation zone over a width greater than 25% and preferably        greater than 40% of the width of the flotation zone in which        said tread elements are situated, said tread elements comprising        front lateral walls and rear lateral walls;    -   (ii) in the front portion of the flotation zone, at least a        portion of the tread elements comprise a rear lateral wall that        is inclined in such a way that the free edge ridge of this wall        is offset toward the rear of the snowshoe compared with the edge        ridge contiguous with the rest of the sole;    -   (iii) in the rear portion of the flotation zone, at least a        portion of the tread elements comprise a front lateral wall that        is inclined in such a way that the free edge ridge of this wall        is offset toward the front of the snowshoe compared with the        edge ridge contiguous with the rest of the sole.

Such a design makes it possible to obtain optimal performance for eachof the zones of the sole. Because the sole is flexible and ergonomic,allowing a rolling of the foot that is similar to normal walking, thevarious zones of the foot are thus specialized, the front zone beingintended more for traction performance, and the rear zone being intendedmore for braking performance. More particularly, crampons inclined inopposite directions between the front and the rear make it possible tooptimize the performance of each of these zones. Furthermore, the frontzone provides good traction and the rear zone provides an optimalbraking force. Furthermore, the profiles of the tread elements createedge ridges which exert particularly effective traction and brakingforces on the snow.

According to one advantageous embodiment, the snowshoe comprises aplurality of substantially elongate peripheral tread elements made ofelastomeric material, oriented in the longitudinal direction of thesnowshoe, arranged over at least one of the lateral overhangs, saidtread elements comprising outside lateral walls (on the side toward theoutside of the snowshoe) and inside lateral walls (toward the middle ofthe sole), at least part of the peripheral tread elements comprising aninside lateral wall that is inclined in such a way that the free edgeridge of this wall is offset towards the centre of the sole comparedwith the edge ridge contiguous with the rest of the sole.

The layout of the peripheral tread elements gives the snowshoe betterstability particularly when the snowshoe is in a laterally inclinedposition, for example along a mountainside. Furthermore, the profiles ofthe tread elements, with an inclined inside lateral wall, create edgeridges which exert particularly effective traction and braking forces onthe snow.

Advantageously, the tread elements are continuous or discontinuous.

Advantageously also, said tread elements pass across the foot zone overa width greater than 50% of the width of the foot zone in which saidtread elements are situated. This arrangement allows better transmissionof force from the foot to the ground.

According to one advantageous embodiment, the tread elements have theirmain axis substantially parallel to the transverse axis of the snowshoe.

According to various embodiment variants, the tread elements aresubstantially rectilinear, are in the shape of a “V”, or are in theshape of an inverted “V” between the front of the snowshoe and the tail.

The layout with one zone in the shape of a “V” and one zone in the shapeof an inverted “V” makes it possible to improve the traction and brakingperformance while respecting the natural roll of the foot in walking.Specifically, the tread elements in the shape of a “V” at the front ofthe snowshoe are able to accentuate traction forces and the treadelements in the shape of an inverted “V” at the rear of the snowshoe areable to accentuate braking forces. The combined use of the “V” shapesand of the inclined walls makes it possible to achieve particularly highlevels of performance.

Advantageously, said tread elements are arranged in such a way thattheir main axis forms an angle, alpha, smaller than 60° and preferablysmaller than 45° with respect to the transverse axis of the snowshoe.

Advantageously also, the front portion of the snowshoe is turned up andalso comprises, on the contact face, a plurality of tread elements.These tread elements are active particularly at the end of the phase ofthe rolling of the foot in order to minimize or avoid the tendency tosideslip and to slide, which tendencies are commonplace when only thefront end of the snowshoe remains in contact with the ground.

According to one advantageous embodiment, the front portion of thesnowshoe corresponds substantially to the front of the foot zone.Dispensing with the shovel tip at the front makes it possible to obtaina snowshoe that is ergonomic and has optimal performance.

According to another advantageous embodiment, the base structurecomprises a reinforcing element, at least a portion of the treadelements being mounted in collaboration with said reinforcing element.

Advantageously, the reinforcing element comprises a main reinforcingelement, comprising at least three sectors substantially in the shape ofa “T” and respectively corresponding with the zones supporting the firstmetatarsus, the fifth metatarsus and the heel, at least a portion of thetread elements being mounted in collaboration with said main reinforcingelement. Such a layout allows the weight of the user to be distributedover a large surface area of the snowshoe. This feature makes itpossible to optimize the flotation of the snowshoe. This layout alsomakes it possible to achieve good stability when walking. This layout isalso perfectly suited to the anatomy of the foot, for increasedeffectiveness and optimal comfort.

Advantageously also, the base structure and the tread elements areelastically deformable. This layout makes it possible to obtain asnowshoe that is flexible enough to adapt to the relief of the ground,but also stiff enough to provide a good level of flotation and a goodpurchase, thanks to the reinforcing element. This feature meets theneeds of physiological walking, also allowing the foot to roll in anergonomic and natural way.

According to one advantageous embodiment, the base structure comprises asolid surface. The absence of latticework, holes or perforationsprovides better flotation and is able to create thermal insulationbetween the snow and the boot.

According to another advantageous embodiment, the base structure is madeof a material of thermoplastic type, preferably comprised in the list ofthe following families: thermoplastic polyurethane, thermoplasticelastomer such as polyethylene vinyl acetate or styrene butadienestyrene for example.

These materials are able to withstand a rigorous environment of use,offer good resistance to wear (particularly by friction) and make itpossible to create a structure that is substantially flexible andparticularly lightweight. All of these features contribute to thecomfort of the user, and afford greater user pleasure. The density ofthe polyethylene vinyl acetate is substantially 0.1 to 0.2, and of thethermoplastic polyurethane or of the thermoplastic elastomer, issubstantially 0.4 to 0.8.

According to yet another advantageous embodiment, the base structurecomprises a secondary reinforcing element having a level of stiffnesslower than that of the main reinforcing element, said secondaryreinforcing element extending between said sectors of the mainreinforcing element, at least a portion of the tread elements beingmounted in collaboration with said secondary reinforcing element. Thislayout makes it possible to provide a good level of flotation, whilemaintaining a structural flexibility that promotes good snowshoeergonomics.

According to another embodiment variant, the tread elements comprisesipes. These sipes are preferably oriented in the same direction as thetread element. The sipes may be external and/or internal. In the latterinstance, in the event of wear, the internal sipes become exposed whenthe level of wear corresponds to the positioning of the internal sipe.

DESCRIPTION OF THE FIGURES

All the embodiment details are given in the following description, whichis supplemented by FIGS. 1 to 4D, which are given solely by way ofnon-limiting examples and in which:

FIG. 1 is a schematic depiction of an example of a snowshoe contactface;

FIG. 2 is a schematic depiction, viewed from above, of a snowshoe ableto use a contact face such as that of FIG. 1;

FIG. 3 is a schematic depiction of the snowshoe of FIG. 2, viewed inperspective;

FIG. 4A is a schematic depiction of an example of a snowshoe contactface laid out flat so that all the zones can be seen in the one sameplane;

FIG. 4B is a view in longitudinal section of the sole of FIG. 4A,illustrating the profiles of the tread elements along the sole;

FIGS. 4C and 4D are views in transverse section of the sole of FIG. 4,at various positions, illustrating the profiles of the tread elementsacross the width of the sole.

DETAILED DESCRIPTION OF THE INVENTION Snowshoe Body And Base Structure

FIGS. 1 to 3 illustrate, from various viewpoints, an example of asnowshoe according to the invention. As is clearly visible in FIGS. 2and 3, the snowshoe 1 comprises a base structure 2 comprising a footzone 3 and a flotation zone 4 which surrounds the foot zone 3 except atthe front of the foot zone where the snowshoe ends, forming a frontportion 7. This front portion comprises a front lip 8 correspondingsubstantially to the front of the foot zone 3. This results in asnowshoe that has no shovel-like front tip, making the ergonomics andwalking comfort considerably better. Furthermore, the user can use theirsnowshoes by walking in a similar way to normal walking in boots,rolling the foot, namely by setting the foot down heel first, followedby the sole of the foot, and finally the front of the foot. The rollingthen continues with the lifting of the heel, keeping the toes on theground. As illustrated, the front lip 8 is advantageously curved inshape, forming a kind of protective shell for the front end of the boot.

On each side of the foot zone 3, the flotation zone 4 comprises alateral overhang 5. At the rear, the flotation zone 2 extends beyond thefoot zone 3 to form a shovel-like rear tip 11. As is clearly visible inFIG. 2, the base structure comprises a solid surface. The flotation zone4 thus affords an optimal weight distribution, for minimal sinking intothe snow, and for well-balanced walking. The continuity of surface alsoprovides good thermal insulation, protecting the feet against becomingcold and wet.

For even better ergonomics and to promote comfort and ease of use, thebase structure 2 is preferably made from an elastically deformablematerial giving it great flexibility in use. The deformability of thebase structure allows the rear tip to flex under the effect of theweight of the walker, when the latter is bringing their heel towards theground and setting it down. The flexibility of the snowshoe also makesit possible to optimize the ergonomic behaviour to be consistent withand to conform to the biomechanics of the foot, which leads to walkingwith a rolling of the foot, as mentioned hereinabove.

The base structure 2 is advantageously made from material ofthermoplastic type, preferably comprised in the list of the followingfamilies: thermoplastic polyurethane, thermoplastic elastomer. Use isadvantageously made of polyethylene vinyl acetate or of styrenebutadiene styrene. The material of the base structure 2 may be expandedor non-expanded, depending on the application.

As shown in the example of FIG. 2, the rear tip 11 is preferablyasymmetric and advantageously comprises a cutout 15 freeing the interiorside. As shown in FIG. 3, the rear tip 11 is raised and/or twistedtoward the outside. It preferably comprises an opening 19.

Tread Elements

The snowshoe 1 comprises a contact face 23 and a securing face 24. Thecontact face 23 advantageously corresponds to the underside surface 17of the base structure 2. A plurality of tread elements 20 made of arubbery material are arranged over all or part of said foot zone 3.These tread elements may be continuous or discontinuous.

As illustrated, the tread elements 20 are of substantially elongateshape and pass across the foot zone 3 over a width greater than at least25% and more preferably greater than 40% of the width of this zone, thewidth being measured at the point at which the tread element concernedis situated. Such a design makes it possible to produce numerousrelatively long successive edge ridges which are effective in tractionand in braking. A maximum of the area of the snowshoe is used to producenumerous elongate edge ridge zones.

In a variant, the tread elements 20 pass across the foot zone 3 over awidth greater than 50% of this zone.

The tread elements may have several types of profile, such as, forexample, a substantially rectilinear profile or a profile in the shapeof a “V”.

A layout with opposing tread elements 20 is illustrated in the exampleof FIGS. 1 and 4. In these examples, at the front of the snowshoe, thetread elements 20 are arranged in a V-shape, with the point of the “V”pointing towards the front of the snowshoe. At the rear of the snowshoe,the elements 20 are arranged in the shape of an inverted “V”, namelywith the point of the “V” pointing towards the rear. These reversearrangements provide better control over traction forces (particularlyusing the tread elements at the front of the snowshoe and illustrated inFIG. 1) and braking forces (particularly using the tread elements at therear of the snowshoe and likewise illustrated in FIG. 1). Severalelements in the shape of a “V” may succeed one another, with or withoutintermediate spaces.

As illustrated in FIG. 1, certain tread elements 20 are arranged in sucha way that their main axis forms an angle, alpha, smaller than 60° andpreferably smaller than 45° with respect to the transverse axis of thesnowshoe.

As illustrated in FIGS. 4A and 4B, said tread elements 20 comprise frontlateral walls 25 and rear lateral walls 26. In the front portion of thefoot zone, at least a portion of the tread elements 20 comprise a rearlateral wall 26 that is inclined in such a way that the free edge ridgeof this wall is offset toward the rear of the snowshoe compared with theedge ridge contiguous with the rest of the sole.

In the rear portion of the foot zone, at least a portion of the treadelements 20 comprise a front lateral wall 25 that is inclined in such away that the free edge ridge of this wall is offset toward the front ofthe snowshoe compared with the edge ridge contiguous with the rest ofthe sole. The inclination of the inclined walls is comprised between 5°and 30°, and more preferably between 8° and 20°.

Furthermore, at least one lateral overhang 5 of the contact face 23comprises a plurality of peripheral tread elements 21 which aresubstantially elongate and oriented in the longitudinal direction of thesnowshoe. In a similar way to the transverse tread elements 20, theperipheral tread elements 21 arranged on the edges and oriented in thelongitudinal direction of the snowshoe, provide an arrangement of activeedge ridges that are able to stabilize the snowshoe well, to prevent itfrom slipping sideways when the walker is on laterally inclined terrain.In this example, the peripheral tread elements 21 give a crenellatedarrangement. This crenellated arrangement has two effects: First, theportions oriented in the longitudinal direction are able to stabilizethe snowshoe on ground that is inclined or has a cross fall. Next, theportions in the transverse direction are able to transmit the tractionand braking forces when the tread elements of the foot zone have littleor no contact with the snow. These peripheral tread elements 21 are alsoable to produce an external grip zone that complements the rest of thearea of the snowshoe.

As illustrated in FIGS. 4C and 4D, the peripheral tread elements 21 haveexternal lateral walls 27 on the snowshoe external side, and internallateral walls 28, toward the inside of the sole.

At least some of the peripheral tread elements 21 comprise an internallateral wall 28 that is inclined in such a way that the free edge ridgeof this wall is offset toward the centre of the sole compared with theedge ridge contiguous with the rest of the sole.

The inclination of the inclined walls is comprised between 5° and 30°,and more preferably between 8° and 20°.

As shown in FIGS. 3 and 4, the front portion 7 of the snowshoe is turnedup and also comprises, on the contact face, a plurality of treadelements 20. These tread elements make it possible to lengthen thetraction zone in order to allow forces to be transmitted all the way tothe end of the phase of the rolling of the foot.

Furthermore, according to a preferred embodiment of the snowshoe, thefront portion 7 of the snowshoe corresponds substantially to the frontof the foot zone 3, as shown for example in FIGS. 2 and 3. Such anarrangement, coupled with the tread elements 20 and 21, makes itpossible to obtain a snowshoe that is perfectly ergonomic, and theperformance of which is appreciably improved. Specifically, the naturalwalking action and the rolling of the foot that conforms to thebiomechanics of the human body means that increased forces can betransmitted to the zone of the sole by comparison with a conventionalsnowshoe. The tread elements therefore receive the mechanical impulsesfrom the walker practically without interference, and can thus convertthese impulses into traction, or else into braking forces, as the casemay be. The traction and braking performance thus obtained exceeds thepotential performance of conventional snowshoes which are marred byimperfect ergonomics and by the presence of a front tip.

In an advantageous variant, the base structure 2 comprises reinforcingelements. To optimize the traction of the snowshoe, at least a portionof the tread elements 20, 21 are mounted in such a way as to collaboratewith at least a portion of the reinforcing elements. The forces appliedby the walker are thus transmitted directly to the tread elements, whichcan thus act directly on the snow, for optimal effectiveness.

REFERENCE NUMERALS EMPLOYED IN THE FIGURES

-   1 Snowshoe-   2 Base structure-   3 Foot zone-   4 Flotation zone-   5 Lateral overhang-   6 Housing-   7 Front portion-   8 Front lip-   9 Lateral rim-   10 Upper cover-   11 Tip-   12 Kick-protection zone-   13 Backstop-   14 Fastener-   15 Tip cutout-   17 Base structure contact underside-   18 Binding element-   19 Rear tip opening-   20 Transverse tread element-   21 Peripheral tread element-   23 Contact face-   24 Front lateral wall-   26 Rear lateral wall-   27 Outside lateral wall-   28 Inside lateral wall

1. A snowshoe having: a base structure forming a flotation zone, saidsnowshoe comprising: a contact face and a securing face, said flotationzone comprising, on the contact-face side: (i) a plurality of treadelements made of elastomeric material and arranged over all or part of afoot zone, said tread elements being of elongate shape, passing acrossthe flotation zone over a width greater than 25% of the width of theflotation zone in which said tread elements are situated, said treadelements comprising front lateral walls and rear lateral walls; (ii) inthe front portion of the flotation zone, at least a portion of the treadelements comprise a rear lateral wall that is inclined in such a waythat the a free edge ridge of this the rear lateral wall is offsettoward the rear of the snowshoe compared with the edge ridge contiguouswith the rest of the sole; (iii) in the rear portion of the flotationzone, at least a portion of the tread elements comprise a front lateralwall that is inclined in such a way that a free edge ridge of the frontlateral wall is offset toward the front of the snowshoe compared withthe edge ridge contiguous with the rest of the sole, wherein saidsnowshoe comprises a plurality of elongate peripheral tread elementsmade of elastomeric material, oriented in the longitudinal direction ofthe snowshoe, arranged over at least one of the lateral overhangs, saidtread elements comprising outside lateral walls and inside lateralwalls, at least part of the peripheral tread elements comprising aninside lateral wall that is inclined in such a way that the free edgeridge of this wall is offset towards the centre of a sole of thesnowshoe compared with the edge ridge contiguous with the rest of thesole.
 2. (canceled)
 3. The snowshoe according to claim 1, wherein theinclination of the inclined walls is between 5° and
 30. 4. The snowshoeaccording to claim 1, wherein said tread elements are continuous ordiscontinuous.
 5. The snowshoe according to claim 1, wherein said treadelements pass across the foot zone over a width greater than 50% of thewidth of the foot zone in which said tread elements are situated.
 6. Thesnowshoe according to claim 1, wherein said tread elements have theirmain axis substantially parallel to the transverse axis of the snowshoe.7. The snowshoe according to claim 1, wherein said tread elements aresubstantially rectilinear.
 8. The snowshoe according to claim 1, whereinsaid tread elements are in the shape of a “V”.
 9. The snowshoe accordingto claim 1, wherein said tread elements are arranged in such a way thattheir main axis forms an angle, alpha, smaller than 60° with respect toa transverse axis of the snowshoe.
 10. The snowshoe according to claim2, wherein the inclination of the inclined walls is between 8° and 20°.11. The snowshoe according to claim 8, wherein the angle alpha issmaller than 45°.